gitignore: gitignore quilt's files

gitignore: ignore quilt's files.
Signed-off-by: Qi Yong <qiyong@fc-cn.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

.gitignore

@@ -34,3 +34,7 @@ include/linux/utsrelease.h
 
 # stgit generated dirs
 patches-*
+
+# quilt's files
+patches
+series